I just installed some lt headers on my 99 gt.. and i can't really tell that much of a difference in the performance of it.. do i need to get a tune or what?.. it sounds much different and much stronger but im not sure whether its any faster.. what should i do?

 

A tune wouldn't hurt, but it's not necessary.

 

Their is a differance in power by a good bit. A tune would help but its not required, however DO NOT RUN THEM OPEN. If you run your headers just open, you WILL fowl your spark plugs.